Dispersed Phase Holdup in Hanson Mixer-Settler Extraction Column

In the present work, dispersed phase holdups have been measured in a Hanson mixer-settler extraction pilot plant with seven stages for two different liquid-liquid systems. The effects of agitation speed, dispersed and continuous phase flow rates have been investigated under a variety of operating conditions. Dispersed phase axial holdup profiles, determined by a sampling method, showed a strong nonuniformity. The results also showed that the dispersed phase holdup changes largely with the direction of mass transfer. Finally, an empirical correlation in terms of physical properties of liquid systems and operating variables was proposed to predict the holdup and good agreement between experimental data and calculated values of holdup was obtained.